한국 증시 Emergency Briefing: 2026-05-31
The KOSPI is hitting record highs driven by semiconductor giants, even as foreign investors pull a record 44 trillion KRW. Samsung Electronics and SK Hynix now make up 50.7% of the KOSPI market cap, creating an extreme concentration, while KOSDAQ is seeing a record influx of foreign capital.
Korean Market Emergency Briefing — 2026-05-31
Market Snapshot
- KOSPI: Settled at the 8,400 level (Up from the previous trading session, hitting a new all-time high)
- KOSDAQ: Continuing its upward trend (Driven by foreign net buying)
- KRW/USD Exchange Rate: 1,495.5 KRW (As of the 29th, down 7.3 KRW from the previous day)
- Market Sentiment: The index is surging due to the unchecked dominance of semiconductors, but gains for individual stocks are extremely limited. A shift in liquidity is underway as capital begins to flow into the KOSDAQ.

Supply & Demand Trends (KOSPI based)
- Foreigners: Net sold 44.7146 trillion KRW (The largest single-month profit-taking in May history) — Massive exodus from KOSPI, while simultaneously pouring a record amount of net buying into the KOSDAQ.
- Institutions: Maintaining a trend of increased net buying — Primarily focused on semiconductors and electronic components.
- Individuals: Profit-taking and mixed sentiment — Net selling in KOSPI, shifting to net buying in KOSDAQ.

Today’s Top 5 Headlines
Foreigners Net Sell 44 Trillion KRW, Record Influx into KOSDAQ
- What happened?: Throughout May, foreigners net sold 44.7146 trillion KRW from the KOSPI, marking their largest profit-taking move ever. At the same time, the KOSDAQ saw a record influx of capital, signaling a rapid shift in market dynamics. Despite hopes for a peace deal between the U.S. and Iran, the foreign exodus remains ongoing.
- Market Impact: Heightened concentration in KOSPI large-caps; growing expectations for a KOSDAQ rebound driven by small-to-mid-cap biotech and tech stocks.
Samsung Electronics & SK Hynix Market Cap Exceeds 50.7%, Extreme Concentration Deepens
- What happened?: As of the 29th, Samsung Electronics and SK Hynix combined to make up 50.7% of the KOSPI market cap, effectively dominating half the market. Even as the KOSPI broke through the 8,400 line to hit an all-time high, a "paradoxical rally" continues where 9 out of 10 stocks are declining.
- Market Impact: Reduced market breadth due to semiconductor dominance; signals of rotation are being watched. Investors in non-semiconductor sectors are feeling increased psychological strain.

U.S.-Iran Peace Negotiation Hopes Drive KOSPI Rebound
- What happened?: The possibility of a peace deal between the U.S. and Iran, combined with positive vibes from U.S. tech stocks, has stimulated buying in Korean semiconductor giants, pushing the KOSPI to record highs daily. Easing geopolitical risks are boosting risk-on sentiment.
- Market Impact: Continued strength in the semiconductor sector; potential for parallel rallies in energy and defense stocks.
KRW/USD Exchange Rate Drops to 1,495.5, Easing Foreign Exit Pressure
- What happened?: On the 29th, the KRW/USD rate fell 7.3 KRW to 1,495.5, continuing a trend of dollar weakness. The combination of expectations for lower global interest rates and a preference for risk assets is strengthening the KRW.
- Market Impact: Reduced pressure on export-oriented corporate earnings and lower foreign currency loss risks may curb further foreign exits.
Seoul FX Market to Launch 24-Hour Non-Stop Trading (June 6)
- What happened?: Starting on the 6th of next month, the Seoul Foreign Exchange market will operate 24 hours a day, excluding weekends and public holidays. With currency exchange becoming possible on domestic holidays, convenience for foreign investors and import/export firms will improve significantly.
- Market Impact: Increased FX market liquidity, expectations for lower exchange rate volatility, and fewer constraints on foreign capital flows.
Leading Sectors & Themes
Semiconductors & Electronic Components
- Trend: Maintaining strength due to strong U.S. tech stocks and continuous AI data center demand. Concentration on Samsung Electronics and SK Hynix remains intense.
- Key Stocks: Samsung Electronics, SK Hynix, SK Biopharmaceuticals.
Secondary Batteries & Materials
- Trend: Gradual upward trend due to expanding ESS (Energy Storage System) demand for AI data centers. Recommendations to increase exposure to Samsung SDI, L&F, and HanJoong NCS.
- Key Stocks: Samsung SDI, L&F, etc.
Biotech & Small-to-Mid Tech (KOSDAQ)
- Trend: With foreign net buying entering the KOSDAQ, capital is starting to be reallocated toward biotech and tech stocks away from semiconductors. KOSDAQ trading volume is increasing.
- Key Stocks: Easing weakness among biotech-related small/mid-caps.
Top Gainers & Losers
Top 3 Gainers
- Samsung Electronics — Leads the index and semiconductor strength.
- SK Hynix — Leads the memory rally, commanding 50% of market cap.
- SK Biopharmaceuticals — Combined strength in electronic components and biotech.
Top 3 Losers
- KOSDAQ Small-to-mid-caps — 1,507 stocks declined (as of the 27th).
- Non-semiconductor Blue Chips — 9 out of 10 KOSPI stocks declined.
- Other Manufacturing — Broad weakness due to capital outflow.
Overseas Market Linkage Points
U.S.-Iran Peace Negotiation Hopes
As of the 31st, reports of direct talks between the U.S. and Iran have fueled hopes of reduced geopolitical risk, stimulating buying in Korean semiconductor and tech stocks. Stronger risk-on sentiment is driving both a stronger KRW and a stock market rebound.
Spillover of U.S. Tech (M7) Strength into Korean Semiconductors
The continuous strength of the Nasdaq 100 and the rising preference for AI-related companies are driving demand for Korean memory chip suppliers, Samsung Electronics and SK Hynix. Korean overnight futures are tending to show strength following the U.S. market close.
Tomorrow’s Checkpoints
- Confirm Foreign Flow Reversal Signals — Check early trading to see if foreigners continue to exit or if they expand net buying in the KOSDAQ at the start of the month.
- Track Semiconductor Concentration Metrics — Watch for widening divergence between the number of advancing stocks (ADR) and the index; look for signs of sectoral rotation.
- Possibility of KRW/USD Entering the 1,490 Range — If the rate drops further, monitor the balance between easing foreign currency loss concerns vs. deepening pressure on export corporate earnings.
Investor Action Items
- Check Semiconductor Concentration: If your portfolio’s allocation to Samsung Electronics and SK Hynix exceeds 30%, consider rebalancing (due to extreme concentration risk).
- Monitor KOSDAQ Opportunities: Identify the timing to increase exposure to biotech/tech stocks based on signals of foreign net buying.
- FX Defense Strategy: Consider additional dollar hedging if the KRW/USD breaks through 1,490, and re-evaluate the impact on export corporate earnings.
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